SPIisLatency and SPRequestDuration Response Headers in SPO Pages

From my blog post (https://sharepointinterface.com/2017/07/07/the-five-minute-page-performance-troubleshooting-guide-for-sharepoint-online/):

UPDATE (3/20/2018): As most of you who have been following-along in your own tenants know, this issue wasn't actually truly resolved last September. For a while, in some cases, it looked like the SPIisLatency and SPRequestDuration headers came back. But the victory was fleeting, and since that time I've continued to get comments from people saying "but I don't see them!" And while I had the headers for a while in my tenant, I haven't seen them in any predictable fashion.

The good news is that after much hounding and making myself a royal pain-in-the-tuckus to Bill Baer and others at Microsoft, it looks like we FINALLY have the right engineering and dev teams engaged to look at this. We got traction on it this week, with multiple repro scenarios and Fiddler traces being passed around ... so I'm truly hopeful we'll see something before long. Stay tuned!